Antenna arrays have a plurality of antennas used to communicate radio frequency (RF) signals through wireless communication links. Antenna arrays provide improved performance relative to a single antenna by providing a better antenna pattern for a coverage area.
Even with an antenna array to provide an improved antenna pattern, signals communicated between communication devices are subject to interference. Buildings, hills and other objects produce multipath wave propagation, and communication devices and energy sources introduce noise, resulting in errors in the signals communicated between communication devices.
To reduce these errors, techniques have been developed to optimise the receive path of a communication device employing an antenna array. By varying the weight of the signals detected by each of the individual antennas in the array, it is possible to vary the antenna pattern to better detect signals from a particular direction or to arrange for non-destructive combination of multipath signals. These techniques adjust the weights of the antenna array signals to maximise the receive path gain by measuring the output of a receiver. However, the weights derived for the receive path does not provide optimum weights for the transmit path.
Accordingly, it is desirable to provide improved antenna array weights for a transmitter.